The invention pertains to a brake mechanism for a rope pulley of a leash that can be mechanically wound and unwound for leading animals, wherein a belt or the rope can be unwound from the rope pulley against the force of a spring and wound onto the rope pulley due to the force of the spring, wherein the brake mechanism comprises a brake button that can be moved from an idle position, in which the rope pulley is freely rotatable, into a functional position, in which the brake button blocks the unwinding of the rope from the rope pulley, wherein the brake button features an upper part that protrudes from the leash housing and enables the user to actuate the brake mechanism, as well as a lower part that cooperates with the rope pulley and is connected to the upper part so that it can pivot, and wherein the lower part can be pivoted in the winding direction of the rope such that, in the functional position of the brake button, the rope is prevented from being unwound from the rope pulley, but can be wound onto the rope pulley. The invention specifically pertains to an automatic dog leash such that the following description primarily refers to such a dog leash, but this does not imply that the invention is limited to such an embodiment. Although the following description also primarily refers to a rope, the leash may also be realized in the faun of a belt.
A brake mechanism of this type is known from DE 20 2007 004 273 U1 of the applicant. Along its circumference, the rope pulley features a plurality of projections that come in contact with the lower part of the brake button in the depressed state. This prevents further unwinding of the rope from the rope pulley. In this depressed state, the lower part frictionally cooperates with the rope pulley such that the lower part pivots during a rotation of the rope pulley in the winding direction and allows a rotation of the rope pulley in the winding direction. When the rope pulley rotates in the unwinding direction again, the lower part pivots back into the blocking position and prevents further unwinding of the rope. This measure simplifies the retrieval of the dog because the rope pulley can be moved in the direction of the dog while the brake button is depressed such that the rope is wound onto the pulley. When the dog leash is subsequently pulled back, the rope pulley slightly rotates in the unwinding direction such that the lower part of the brake button pivots into its functional position and prevents further unwinding of the rope from the pulley. Such a friction element makes it possible to prevent annoying noises like those of a ratchet mechanism.
It was determined that the assembly of such a dog leash is associated with certain problems. It is necessary, in particular, to exactly observe the distance, by which the brake button is displaced relative to the friction surface on the rope pulley, in order to achieve sufficient friction between the lower part and the circumferential surface. The friction element between the lower part and the rope pulley is also subjected to considerable wear. It was furthermore determined that constant use and progressive wear may cause the lower part to no longer pivot back sufficiently such that the leash remains fully functional, but the retrieval process is associated with undesirable noises.